先查询出日期数据(当前日期往前推12个月)

select bb.date
		from (
			select @num := @num + 1,date_format(adddate(date_sub(date_sub(curdate(),interval 12 month),interval 1 month),interval @num month),				'%Y-%m') as date
			from mysql.help_topic,(select @num := 0) as t
			where adddate(date_sub(curdate(),interval 12 month),interval @num month) <= date_format(curdate(),'%Y-%m-%d')
			order by date
		) as bb
		group by bb.date

日期数据展示

将上方日期数据作为主表进行查询(查询当前月往前推12个月的数据)

select a.date,ifnull(b.pc_order_price,0) pc_order_price,ifnull(app_order_price,0) app_order_price,ifnull(order_price,0) order_price from 
(select bb.date
		from (
			select @num := @num + 1,date_format(adddate(date_sub(date_sub(curdate(),interval 12 month),interval 1 month),interval @num month),				'%Y-%m') as date
			from mysql.help_topic,(select @num := 0) as t
			where adddate(date_sub(curdate(),interval 12 month),interval @num month) <= date_format(curdate(),'%Y-%m-%d')
			order by date
		) as bb
		group by bb.date) a
left join (
SELECT 	date, 
				round((sum(pc_order_price) / 10000),4) pc_order_price,
				round((sum(app_order_price) / 10000),4) app_order_price,
				round((sum(pc_order_price) / 10000) + (sum(app_order_price) / 10000),4) order_price
FROM
	(
		SELECT-- f.pay_time,
					-- f.invoice_time,
		date_format( f.order_time, '%Y-%m' ) AS date,
		case when order_mode = 0
				 then f.order_price
				 else 0 end pc_order_price,
		case when order_mode = 1
				 then f.order_price
				 else 0 end app_order_price
	FROM
		表名 f
	WHERE
		f.del_flag = 0 
		AND f.order_time >= date_sub(curdate(),interval 12 month)
	) r 
GROUP BY
	date) b on a.date = b.date;
	

最终数据展示